Horizontal steam generator with a riser manifold



HORIZONTAL STEAM GENERATOR WITH A RISER MANIFOLD Filed May 31, 1962 OOO INVENTORS. DAVID B. SMITH BY KENNETH E. WEBSTER United States Patent 7 3,123,053 HQREZGNTAL STEAM GENERATGR WITH A RISER MANHGLD Kenneth E. Webster and David B. Smith, Chattanooga,

Tenn, assignors to Combustion Engineering, Inc,

Windsor, Conn, a corporation of Delaware Filed May 31, 1962, Ser. No. 199,048 12 Cla ms. (Cl. 123-73) This invention relates generally to a vapor generating unit and, more particularly, to a shell and tube type, natural circulation generator incorporating a heating medium consisting of a heated fluid.

At the present time high temperature fluids are made available for heating purposes in such industries as petroleum refining, chemical manufacturing and other diverse industries. From these fluids heat may be extracted to vaporize a liquid such that the so-created vapor can perform useful functions. The present invention relates to such a vapor generating system wherein pressurized water, sodium, stream, gases or other fluid substances in a hot condition are passed through heat exchanger tubes housed in a shell containing a vaporizable substance, such as water, whereby vapor is generated.

Installations which utilize the present type of vapor generator oftentimes have space limitations which necessitate the use of a generator which is highly compact in form. The present unit provides an improved vapor generator which emphasizes a compact form while permitting highly eflioient operation including a high rate of heat transfer and an adequate circulation of the vaporizable medium.

The present invention contemplates directly joining a vapor collector drum which houses a plurality of vapor separators and other vapor processing equipment, to a horizontally oriented vapor generating chamber thereby forming a unitary pressure vessel while, at the same time, incorporating a means which is Wholly enclosed within the vessel to isolate the flows of vaporizable fluid and vapor-liquid mixture. This feature makes it possible to employ the entire volume of the vessel as usable volume and to keep to a minimum the piping appendages which heretofore increased the space requirements of such units.

For a better understanding of the invention, its advantages and the specific objects obtained by its use, reference is made to the following description with the accompanying drawings which disclose a preferred embodiment of the invention.

0f the drawings:

FIG. 1 is a vertical side section of the invention;

FIG; 2 is a transverse section through the generator along line 2-2 of FIG. 1; and

FIG. 3 is a transverse section through the vapor collecting drum along line 3-3 of FIG. 1.

The vapor generating unit comprises a horizontally elongated, substantially cylindrical shell 11 formed of a tubular wall having its end closed by means of dishshaped end walls 12 and 13'. Adjacent to, but removed from end Wall 13 is' located a tube sheet 14 which is positioned transversely to the centerline of the tubular wall thereby dividing the shell 11 into a vapor generation chamber 15- and a hot fluid chamber 16. The hot fluid chamber 16 is, in turn, divided into inlet and outlet portions, 17 and =18 by means of alateral divider plate 19 whichis attached'to the end wall 13 and to the tube sheet 14. Nozzles 2i) and'21 communicate with the hot fluid inlet and outlet chambers, 17 and 18' respectively, thereby providing a means to maintain a continuous flow of heating fluid between the generator and a source (not shown) and circulate the heating medium through the generator.

Tube sheet 14 possesses a plurality of tube seats 22 Patented Mar. 3, 1954 which receive the ends of Ushaped heat exchanger tubes, attaching the same to the tube sheet. The tubes are arranged in a cluster or bundle 23, which substantially fills the vapor generation chamber 15 with supports 24 being provided to maintain the tubes in alignment Within the chamber. By means of this arrangement a large amount of heating surface is made available for the generation of vapor.

Upon the upper surface of the vapor generating shell M is positioned a cylindrical vapor collectingdrum 25 whose axis is normal to the longitudinal axis of the shell 1-1. The upper end of the drum 25 is closed by means of a dish-shaped end Wall 26 and the lower end is closed by that portion of the vapor generating shell 11 which underlies the drum 25. The resulting structure gives rise to a unitary vapor generator consisting of both a vapor generation chamber 15 and a vapor collecting chamber 27.

The portion of the wall of the vapor generating shell 11 which underlies the vapor collecting drum 25 is provided with a plurality of apertures 28 and 29 permittingfluid communication between the chamber and the drum. in order to separate the two distinct fluid flows which must pass between the vapor generation chamber 15 and the vapor collecting drum 25, means are provided to isolate the rising flow of vapor-liquid mixture which is emited from the vapor generating chamber 15 into the vapor collecting drum 25 from the downward flow of vaporizable fluid from the drum to the vapor generating chamber. This means consists ofa manifold '39 which covers those apertures 23 through which the rising vaporliquid mixture passes thereby forming a mixture cavity 31 at the base of the vapor collecting drum. The apertures 29 which carry the downward flow of fluid from the drum 25 to the vapor generating chamber 15 are left exposed to the vapor collecting chamber 27.

An annularly arranged bank of vapor separators 32 communicate with the mixture cavity 31 by means of upstanding conduits 3-3 which attach each separator to the manifold 30. The separators 32 receive the rising flow of mixture, separating, by centrifugal means, the vapor from the liquid; the separated vapor passing through a screen drier 3 4 which is attached to the upper end ofthe vapor collecting drum 25 and on out the vapor outlet nozzle 35 provided in the upper end wall 26 of the vapor collecting drum while the liquid falls to the bottom of the drum where it mixes with the makeup fluid which enters the drum through inlet port 35 and passes to the vapor generation chamber through the downcomer aperatures 29.

Within the vapor generation chamber 15 a means is provided to' divert the flow of down-coming fluid around the periphery of the tube bundle 23 to the bottom of the chamber. This means consists of a pair of arouately formed baffle plates 37 which are attached to the shell 11' between the tube bundle 23 and the wall of the shell. The plates are provided on one edge with upturned'flanges 3-8 which attach to the upper portion-of the shell wall. The edges of the plates are spaced one from another to provide channels 39 extending inwardly from both ends of the baflie. An arcuate indenture 40 is made in each plate intermediate the ends of the edges formed with the flanges 38. These indentures 49 are positioned directly beneath the riser apertures 23 to provide a means which ermits unencumbered flow of the vapor-liquid mixture into the apertures 28. The channels 39 and the space created by the indentures 40 serve to permit the upwardly flowing vapor-liquid mixture to pass from the vapor generating chamber 15 through'the riser apertures 28 into the mixture cavity 31 formed bythe manifold 39.

As shown in FIGS. 1 and 2 a portion of the upper half of the shell may be formed of an oversize-d thickness so as to reinforce the shell in the area of attachment of the vapor collecting drum. This reinforced area forms a pad 41 which serves to take up the stresses de veloped in the shell 11 by the attachment of the vapor collecting drum 25 thereto.

The operation of the herein disclosed generator is as follows: a vaporizable fluid such as water enters the vapor collecting drum 25 through inlet port 36 and passes downwardly through the downcomer apertures 29 into the vapor generation chamber 15 substantially filling the same. Baffle plates 37 serve to divert the flow of liquid around the tube bundle 23 to the lower portion of the vapor generation chamber 15 so that the heating surface of all of the tubes of the tube bundle 23 will be utilized for vapor generating purposes. Heating fluid from a source (not shown) enters the hot fluid inlet chamber 17 through nozzle 2% and flows through the vapor generation chamber 15 through the tubes of the tube bundle 23 and out through the outlet chamber 18 and nozzle 21. Heat is given up by the hot fluid thereby transforming a portion of the vaporizable fluid which surrounds the tubes into vapor. Due to the thermal siphonic effect which accompanies such a transformation the vapor-liquid mixture rises to the upper portion of the vapor generating chamber 15 flowing toward the riser apertures 28 through the channels 39 and space created by the indentures it? in the baffle. The mixture continues on its upward path through the riser apertures 28 into the manifold cavity 31 from whence it passes into the separators 32 through the elongated conduits 33 which connect the separators to the manifold 30. By means of centrifugal action the mixture is separated into vapor and liquid, with the vapor flowing upwardly out of the separators 32 and the liquid being discharged to the bottom of the vapor collecting chamber 27. The upwardly flowing vapor passes through the screen drier 34 where any remaining particles of liquid are removed therefrom and continues out of the drum by means of the outlet nozzle 35 provided in the upper end wall 26. The liquid, which is discharged from the separators, falls to the bottom of the vapor collecting chamber 27 where it mixes with the incoming make-up fluid which enters through the port 36 and passes through the downcomer apertures 29 into the vapor generation chamber 15 where the cycle is repeated.

The vapor generator described herein provides a unit which requires a minimum amount of operating space. By joining the vapor collecting drum directly to the vapor generating shell there is thus eliminated the connecting conduits which heretofore had been necessary to connect the two in fluid circulation. these conduits has permitted a decrease in the over-all height of the generator. By enclosing the downcomer and riser paths within the confines of the generator vessel there is thus eliminated the piping appendages which added to the cost of the units and necessitated additional operating space.

The advantages derived from the instant design do not sacrifice operating elliciencyi The generator provides for maximum circulation and allows for a reduced circulating head since the length of the paths of circulation are reduced.

While there has been disclosed a particular embodiment of the invention, this disclosure is intended to merely illustrate and not to limit the inventive concept. For example, the present invention is equally applicable to vapor generators wherein the heat exchanger tubes take the form of straight tubes interconnecting a pair of hot fluid chambers, each being located at either end of the shell. It is understood that these changes, as well as others, may be made in the form of the disclosed apparatus without departing from the spirit of the invention covered by the appended claims. r

What is claimed is:

l. A vapor generator comprising an evaporation chamber defined by an elongated shell and a vapor collector f Moreover, elimination of borne by said shell, said vapor collector having a wall common to said shell; a tube bundle substantially filling said chamber; means for passing a heating fluid through said tube bundle; means for admitting vaporizable fluid to said generator; means forming apertures in said common wall effecting communication between said evaporation chamber and said vapor collector; means segregating said apertures into downcomer and riser passages; baflie means directing said vaporizable fluid from said downcomer passages to the bottom of said chamber and for directing said vaporizable fluid in a heated condition to saidriser apertures; and vapor outlet means in said vapor collector for removing vapor from said generator.

2. A vapor generator comprising an evaporation chamber defined by an elongated shell and a vapor collector borne by said shell, said vapor collector having a wall common to said shell; a tube bundle substantially filling said chamber; means for passing a heating fluid through said tube bundle; means for admitting a vaporizable fluid to said generator; means forming apertures in said common wall effecting communication between said evaporation chamber and said vapor collector; manifold means segregating said apertures into a plurality of downcomer passages and a plurality of riser passages; baflle means for directing said vaporizable fluid from said downcomer passages to the bottom of said evaporation chamber and for directing said vaporizable fluid in a heated condition to said riser apertures; and vapor outlet means in said vapor collector for removing vapor from said generator.

3. A vapor generator comprising an evaporation chamber defined by an elongated shell and a vapor collector borne by said shell, said vapor collector having a wall common to said shell; a tube bundle substantially filling said chamber; means for passing a heating fluid through said tube bundle; means for admitting a vaporizable fluid to said generator; means forming apertures in said common wall effecting communication between said evaporation chamber and said vapor collector; manifold means segregating said apertures into a plurality of downcomer passages and a plurality of riser passages; baflie means comprising a pair of arcuately formed, elongated plates positioned between said tube bundle and the wall of said shell defining a downcomer path around the periphery of said tube bundle, said path communicating with said downcomer passages; said plates being spaced apart adjacent said riser passages thereby effecting communication between said evaporation chamber and said riser passages; and vapor outlet means communicating with said vapor collector to remove vapor from said generator.

4. A vapor generator comprising an evaporation chamber defined by an elongated shell and a vapor collector borne by said shell, said vapor collector having a wall common to said shell; a tube bundle substantially filling said chamber; means for passing a heating fluid through said tube bundle; means for admitting a vaporizable fluid to said generator; means forming apertures in said common wall efiecting communication between said evaporation chamber and said vapor collector; manifold means positioned within said vapor collector enveloping a plurality of said apertures thereby segregating said apertures into a plurality of downcomer passages and a plurality of riser passages; vapor separator means communicating with said manifold, said separator means having liquid discharge means communicating with said downcomer passages and means effecting vapor discharge into said vapor collector; baflie means for directing said vaporizable fluid and the liquid discharge from said vapor separators from said downcomer passages to the bottom of said evaporation chamber and for directing said vaporizable fluid in a heated condition to said riser apertures; and vapor outlet means communicating with said vapor collector for removing vapor from said generator.

5. A vapor generator comprising an evaporation chamber defined by an elongated shell and a vapor collector borne by said shell, said vapor collector having a wall common to said shell; a tube bundle substantially filling said chamber; means for passing a heating fluid through said tube bundle; means for admitting a vaporizable fluid to said generator; means forming apertures in said common Wall effecting communication between said evaporation chamber and said vapor collector; manifold means positioned within said vapor collector enveloping a plurality of said apertures thereby segregating said apertures into a plurality of downcomer passages and a plurality of riser passages; vapor separator means communicating with said manifold, said separator means having liquid discharge means communicating with said downcomer passages and means effecting vapor dishcarge into said vapor collector; baffle means comprising a pair of arcuately formed, elongated plates positioned between said tube bundle and the wall of said shell defining a downcomer path around the periphery of said tube bundle, said path communicating with said downcomer passages; said plates being spaced apart adiacent said riser passages thereby effecting communication between said evaporation chamber and said riser passages; and vapor outlet means communicating with said vapor collector to remove vapor from said generator.

6. A vapor generator comprising an evaporation chamber defined by a horizontally oriented, elongated, cylindrical shell; a vapor collector borne by the upper surface of said shell; a portion of said surface forming the lower end wall of said collector; said vapor collector comprising a cylindrical drum having its upper end closed by a head; a tube sheet within said evaporation chamber forming a heating fluid portion therein; partition means dividing said portion into inlet and outlet chambers; a tube bundle substantially filling said chamber, said tube bundle being formed of a plurality of U-tubes having their ends attached to said tube sheet thereby forming heating fluid paths from said heating fluid inlet chamber to said heating fluid outlet chamber; means for admitting a vaporizable fluid to said generator; means forming apertures in said wall common to said vapor collector and said evaporation chamber effecting communication therebetween; means segregating said apertures into downcomer and riser passages; baffle means for directing said vaporizable fluid from said downcomer passages to the bottom of said chamber and for directing said vaporizable fluid in a heated condition to said riser apertures; and vapor outlet means in said vapor collector for removing vapor from said generator.

7. A vapor generator comprising an evaporation chamber defined by a horizontally oriented, elongated, cylindrical shell; a vapor collector borne by the upper surface of said sheil, a portion of said surface forming the lower end wall of said collector; said vapor collector comprising a cylindrical drum having its upper end closed by a head; a tube sheet Within said evaporation chamber forming a heating fluid portion therein; partition means dividing said portion into inlet and outlet chambers; a tube bundle substantially fillin said chamber, said tube bundle being formed of a plurality of U-tubes having their ends attached to said sheet thereby forming heating fluid paths from said heating fluid inlet chamber to said heating fluid outlet chamber; means for admitting a vaporizable fluid to said generator; means forming apertures in said common Wall effecting communication between said evaporation chamber and said vapor collector; manifold means segregating said apertures into a plurality of downcomer passages and a plurality of riser passages; baflie means for directing said vaporizable fluid from said downcomer passages to the bottom of said evaporation chamber and for directing said vaporizable fluid in heated condition to said riser apertures; and vapor outlet means in said vapor collector for removing vapor from said generator.

8. A vapor generator comprising an evaporation chamber defined by a horizontally oriented, elongated, cylindrical shell; a vapor collector borne by the upper surface of said shell, a portion of said surface forming the lower end wall of said vapor collector; said vapor collector comprising a cylindrical drum having its upper end closed by a head; a tube sheet within said evaporation chamber forming a heating fluid portion therein; partition means dividing said portion into inlet and outlet chambers; a tube bundle substantially filling said chamber, said tube bundle being formed of a plurality of U-tubes having their ends attached to said tube sheet thereby forming heating fluid paths from said heating fluid inlet chamber to said heating fluid outlet chamber; means for admitting a vaporizable fluid to said generator; means forming apertures in the wall common to said evaporation chamber and said vapor collector eflecting communication therebetween; manifold means segregating said apertures into a plurality of downcomer passages and a plurality of riser passages; baflie means comprising a pair of arcuately formed, elongated plates positioned between said tube bundle and the Wall of said shell defining a downcomer path around the periphery of said tube bundle, said path communicating with said downcomer passages; said plates being spaced apart adjacent said riser passages thereby effecting communication between said evaporation chamber and said riser passages; and vapor outlet means communicating with said vapor collector to remove vapor from said generator.

9. A- vapor generator comprising an evaporation chamber defined by a horizontally oriented, elongated, cylindrical shell; a vapor collector borne by the upper surface of said shell, a portion of said surface forming the lower end wall of said collector; said vapor collector comprising a cylindrical drum having its upper end closed by a head; a tube sheet within said evaporation chamber forming a heating fluid portion therein; partition means dividing said portion into inlet and outlet chambers; a tube bundle substantally filling said chamber, said tube bundle being formed of a plurality of U-tubes having their ends attached to said tube sheet thereby forming heating fluid paths from said heating fluid inlet chamber to said heating fluid outlet chamber; means for admitting a vaporizable fluid to said generator; means forming apertures in the wall common to said evaporation chamber and said vapor collector effecting communication therebetween; manifold means positioned within said vapor collector enveloping a plurality of said apertures thereby segregating said apertures into a plurality of downcomer passages and a plurality of riser passages; vapor separator means communicating with said manifold, said separator means having liquid discharge means communicating with said downcomer passages and means effecting vapor discharge into said vapor collector; baflle means for directing said vaporizable fluid and the liquid discharge from said vapor separators from said downcomer passages to the bottom of said evaporation chamber and for directing said vaporizable fluid in a heated condition to said riser apertures; and vapor outlet means communicating with said vapor collector for removing vapor from said generator.

10. A vapor generator comprising an evaporation chamber defined by a horizontally oriented, elongated cylindrical shell; a vapor collector borne by the upper surface of said shell, a portion of said surface forming the lower end Wall of said collector; said vapor collector comprising a cylindrical drum having its upper end closed by a head; a tube sheet within said evaporation chamber forming a heating fluid portion therein; partition means dividing said portion into inlet and outlet chambers; a tube bundle substantally filling said evaporation chamber, said tube bundle being formed of a plurality of U-tubes having their ends attached to said tube sheet thereby forming heating fluid paths from said heating fluid inlet chamber to said heating fluid outlet chamber; means for admitting a vaporizable fluid to said generator; means forming apertures in the wall common to said evaporation chamber and said vapor collector effecting communication therebetween; manifold means positioned within said vapor collector enveloping a plurality of said apertures thereby segregating said apertures into a plurality of downcomer passages and a plurality of riser pasages; vapor separator means communicating with said manifold, said separator means having liquid discharge means communicating with said downcomer passages and means effecting vapor discharge into said vapor collector; baflle means comprising a pair of arcuately formed, elongated plates positioned between said tube bundle and the walls of said shell defining a downcomer path around the periphery of said tube bundle, said path communicating with said downcomer passages; said plates being spaced adjacent said riser passages thereby eflecting communication between said evaporation chamber and said riser passages; and vapor outlet means communicating with said vapor collector to remove vapor from said generator.

11. A vapor generator comprising an evaporation chamber defined by an elongated shell and a vapor collector borne by the wall thereof, that portion of said Wall which bears the vapor collector being of a greater thickness than the remainder thereof; said portion of said Wall being common to said evaporation chamber and said vapor collector; a tube bundle substantially filling said chamber; means for passing a heating fluid through said tube bundle; means for admitting a vaporizable fluid to said generator; means forming apertures in said common wall effecting communication between said evaporation chamber and said vapor collector; manifold means segregating said apertures into a plurality of downcomer passages and a plurality of riser passages; baflle means for directing said vaporizable fluid from said downcomer passages to the bottom of said evaporation chamber and for directing said vaporizable fluid in a heated condition to said riser apertures; and vapor outlet means in said vapor collector for removing vapor from said generator.

12. A vapor generator comprising an evaporation chamber defined by a horizontally oriented, elongated, cylindrical shell; a vapor collector borne by the upper surface of the wall of said shell; that portion of said wall which bears the vapor collector being of a greater'thickness than the remainder thereof; a portion of said surface forming the lower end wall of said collector; said vapor collector comprising a cylindrical drum having its upper end closed by a head; a tube sheet within said evaporation chamber forming a heating fluid portion therein; partition means dividing said portion into inlet and outlet chambers; a tube bundle substantially filling said evaporation chamber, said tube bundle being formed of a plurality of U-tubes having their ends attached to said tube sheet thereby forming heating fluid paths from said heating fluid inlet chamber to said heating fluid outlet chamber; means for admitting a vaporizable fluid to said generator; means forming apertures in said wall common to said vapor collector and said evaporation chamber eflecting communication therebetwecn; means segregating said apertures into downcomer and riser passages; bafile means for directing said vaporizable fluid from said downcomer passages to the bottom of said chamber and for directing said vaporizable fluid in a heated condition to said riser apertures; and vapor outlet means in said vapor collector for removing vapor from said generator.

References Cited in the file of this patent UNITED STATES PATENTS 630,023 Baker Aug. 1, 1899 2,560,070 Bloomer July 10, 1951 2,862,479 Blaser et a1. Dec. 2, 1958 

1. A VAPOR GENERATOR COMPRISING AN EVAPORATION CHAMBER DEFINED BY AN ELONGATED SHELL AND A VAPOR COLLECTOR BORNE BY SAID SHELL, SAID VAPOR COLLECTOR HAVING A WALL COMMON TO SAID SHELL; A TUBE BUNDLE SUBSTANTIALLY FILLING SAID CHAMBER; MEANS FOR PASSING A HEATING FLUID THROUGH SAID TUBE BUNDLE; MEANS FOR ADMITTING VAPORIZABLE FLUID TO SAID GENERATOR; MEANS FORMING APERTURES IN SAID COMMON WALL EFFECTING COMMUNICATION BETWEEN SAID EVAPORATION CHAMBER AND SAID VAPOR COLLECTOR; MEANS SEGREGATING SAID APERATURES INTO DOWNCOMER AND RISER PASSAGES; BAFFLE MEANS DIRECTING SAID VAPORIZABLE FLUID FROM SAID DOWNCOMER PASSAGES TO THE BOTTOM OF SAID CHAMBER AND FOR DIRECTING SAID VAPORIZABLE FLUID IN A HEATED CONDITION TO SAID RISER APERTURES; AND VAPOR OUTLET MEANS IN SAID VAPOR COLLECTOR FOR REMOVING VAPOR FROM SAID GENERATOR. 